Severe Wind, Hail & Electrical Storms

It is the guides responsibility to be on top of:

1. Pre-Activity: Have reviewed the weather forecast prior to meeting clients

2. During Activity: Constantly monitor the rain forecast through out the day guiding

The Hazardous weather trigger events – Weather Warnings and Weather Forecasts are considered when applying this checklist

Identify

• Weather conditions are monitored during periods of severe weather

• Weather warnings and forecasts, rain and wind radars are monitored during periods of severe weather

Prepare

• Participants are advised of weather warnings and anticipated conditions

• The campsite and/or activity site is secured against wind and/or hail damage

• The time delay between any lightening flashes and the sound of thunder is monitored to determine the distance from the storm

• Minimise exposure in the first place (eg. don't be on an exposed ridge during a storm, plan to finish activities before a storm is due, etc)

Immediate actions

• Seek shelter in an appropriately robust and protected place

• Hard–top shelter is sought during severe wind or hailstorms; which may include buildings, vehicles or rock shelters

• During lightening activity tall trees, towers or other isolated tall structures are avoided. If caught in an open area participants are advised to sit on a backpack or other equipment to insulate from any lightening ground strikes

The principles for thinking about lightning are:

• Lightning takes the path of least resistance (don't be that path for the lightning)

• Understand the ball of lightning principle. (Roll an imaginary 60-meter sphere across the landscape and look at where it touches. Places that the sphere makes contact with - treetops, fence posts, and golfers - are potential lightning targets. Make sure the ball touches something else first)

• Minimise damage to everyone in your group (get people to put their feet together, squat and sit on packs/mats, etc)

• Minimise losses (if possible, spread out - that way if lightning does strike only one person gets hit, not everyone)

Other recommended practices:

• Putting your feet together significantly reduces the effects of ground current which causes about 50% of all lightning fatalities

• Flash to Bang interval: count the delay between seeing a lightning flash, to hearing thunder. Every 3 seconds of delay between a flash to thunder, roughly equates to a distance of 1 kilometre. You should seek a safe location whenever the Flash to Bang interval is less than 30 seconds (10 km) distance.

• Spread the group out (5 to 10m between people).

• As a solo guide, it is recommended to give emergency communications devices (eg mobile phone or PLB) to someone who is not the guide. If you’re struck, someone else can call for help.

• With 2 or more guides, you should take half the group each and spread out so that both guides are not injured in the event of a strike. There should be 60 to 100 metres between the two parties.

• If your hair stands on end and/or hear ‘crackling noises’, lightning is about to strike! Assume a crouched position with your feet together (or sit with your feet tucked in close to your body) and head down with your hands on your knees.

• You should avoid:

  • exposed ridges (seek a depression in the landscape)

  • bare/exposed rock (especially ironstone)

  • small caves and overhangs (Rock shelters, cave entrances and overhangs are especially hazardous because lightning travels along vertical surfaces to reach the ground. When lightning needs to jump the gap, any object bridging the gap can help conduct the current.)

  • solitary trees

  • water (puddles, or any larger body of water) (Water is conductive and your head poking up is the highest point on a large flat surface. If lightning strikes water, the electricity spreads outward, mostly over the surface.)

  • conductive equipment or infrastructure (eg. large amounts of climbing hardware: carabiners, descenders, ascenders, etc, but also fences, handrails, lookouts, metal stairs, bridges).

Evacuate or Recover

• Participants are evacuated to a safe area if shelter-in-place is not possible

Report

• The Guide communicates details of additional actions and/or evacuations to the Operations Manager at an appropriate time

• Guide completes INCIDENT REPORT within 48hours of evacuation

More info on the ball of lightning principle: https://what-if.xkcd.com/16/ (here is a great video showing how it looks: https://www.youtube.com/watch?v=4q6gHWN8fDE )

Some other useful Q and A about lightning: http://www.pbs.org/wgbh/nova/earth/dwyer-lightning.html

• Lightning can travel many kilometres through the air, beyond the range of thunder, to locations where there is blue sky overhead. It is possible to be outside, not hear any thunder or see any clouds, and still be struck by lightning.

• Lightning strikes involving people: 10% result in deaths, 90% result in injuries.

• There are 5 to 10 deaths from lightning per year in Australia.

• About 80% of survivors have serious long-term disabilities.

How lightning injures and kills:

• Direct strike - statistics show that death resulted in over 70 % of cases.

• Side flash/splash - e.g. standing near a tree - this can be as serious as a direct strike.

• Contact potential - physical contact with struck object has similar consequences to direct strike. (eg. leaning on a fence)

• Ground Strike/Step voltage - lightning impulse traveling through/on ground and may pass through one limb/part and out another. Injuries include burns and paralysis but these are usually temporary.

• Surge propagation - person close to or in contact with an electrical appliance or power /communication line. Serious injury and death is not common.

• Blast Effect - Lightning victims are sometimes thrown violently against an object, or are hit by flying fragments (e.g., a shattered tree), so first aid may have to include treatment for traumatic injury.